1. Field of the Disclosure
The present application relates to a liquid crystal display device.
2. Description of the Related Art
A variety of display devices for displaying information are being developed. The display devices include liquid crystal display (LCD) devices, plasma display panel devices, electrophoresis display devices, organic electro-luminescence display device, and semiconductor light-emitting display devices, as examples. Among these display devices, liquid crystal display devices have the features of light weight, slimness, high brightness, full-colors, easily enlarged size and so on. As such, the liquid crystal display devices are considered to be the main trend of display devices.
FIG. 1 is a block diagram showing an LCD device of the related art.
Referring to FIG. 1, the related art LCD device includes a liquid crystal panel 1, a timing controller 10, a gate driver 20, a data driver 30, a power supplier 40, a gamma voltage generator 50 and a memory 60.
The liquid crystal panel 1 includes a plurality of gate lines GL1˜GLn and a plurality of data lines DL1˜DLm formed by extending along a direction crossing the plurality of gate lines GL1˜GLn. The plurality of gate lines GL1˜GLn and the plurality of data lines DL1˜DLm crossing each other define a plurality of pixel regions. A thin film transistor 11 is formed on each pixel region. The plurality of gate lines GL1˜GLn are electrically connected to the gate driver 20. The plurality of data lines DL1˜DLm are electrically connected to the data driver 30.
The timing controller 10 derives gate control signals and data control signals using control signals received through an external interface. The gate control signals are used to control the gate driver 20. As such, the gate control signals are applied to the gate driver 20. The data control signals are used to control the data driver 30. As such, the data control signals are applied to the data driver 30. Also, the timing controller 10 transfers data received through the external interface to the data driver 30.
The power supplier 40 generates drive voltages necessary to drive the timing controller 10, the gate driver 20, the data driver 30 and the gamma voltage generator 50. Also, the power supplier 40 applies the drive voltages to the timing controller 10, the gate driver 20, the data driver 30 and the gamma voltage generator 50.
The memory 60 stores initial data necessary to drive the timing controller 10. The memory 60 applies the initial data to the timing controller 10 when the timing controller 10 is initially started.
The gamma voltage generator 50 generates a plurality of gamma voltages by voltage-dividing a high potential power voltage based on a low potential power voltage. The high and low potential power voltages are applied from the power supplier 40 to the gamma voltage generator 50. The plurality of gamma voltages is applied to the data driver 30. The data driver 30 converts the data received from the timing controller 10 into a data voltage by selecting at least one among the plurality of gamma voltages according to the data and adding the selected gamma voltages. Also, the data driver 30 applies the data voltages to the thin film transistors 11 through the plurality of data lines DL1˜DLm and enables gray levels to be displayed.
The gamma voltage generator 50 of the related art LCD device is configured using either arrangement of resistors or an integrated circuit IC chip.
Both the method using the arrangement of resistors and the method using the IC chip must enable the gamma voltage generator 50 to be mounted on a printed circuit board PCB. Due to this, the PCB must be large-sized, and furthermore wirings connecting the PCB with the data driver 30 must be complex.
If the gamma voltage generator 50 is configured using the arrangement of resistors, it is difficult to adjust the gamma voltages. Moreover, a lot of time must be required for the adjustment of gamma voltages.
The gamma voltage generator 50 can be configured using a programmable gamma IC chip. The gamma voltage generator 50 using the IC chip becomes easier to adjust the gamma voltages compared to that using the arrangement of resistors. However, the gamma voltage generator 50 using the IC chip must include a memory, an analog-to-digital converter and an I2C bus transceiver. As such, the circuit configuration of the LCD device must be complex, and manufacturing costs of the LCD device must increase.